PATIENT CHARACTERISTICS: Age: 18 and over Performance status: Karnofsky 50-100% Life expectancy: Not specified Hematopoietic: Absolute neutrophil count at least 1,500/mm3 Platelet count at least 100,000/mm3 Hepatic: Bilirubin no greater than 1.5 times upper limit of normal (ULN) SGOT and SGPT no greater than 2 times ULN (6 times ULN if documented liver metastases present) Alkaline phosphatase no greater than 2 times ULN (6 times ULN if documented liver metastases present) Renal: Creatinine no greater than 1.5 times ULN Cardiovascular: No New York Heart Association class III or IV symptomatic congestive heart failure No serious cardiac arrhythmia No unstable angina No myocardial infarction within the past 6 months Pulmonary: No interstitial pneumonia No extensive and symptomatic fibrosis of the lung Other: Not pregnant or nursing Negative pregnancy test Fertile patients must use effective contraception during and for 6 months after study No known peripheral neuropathy (absence of deep tendon reflexes as the sole neurologic abnormality allowed) No diabetes or active infection No known dihydropyrimidine dehydrogenase deficiency